April 4 will mark the 45th year since the assassination of Dr. Martin Luther King at the Lorraine Motel in Memphis. Dr. King, 39, at the time, has now been gone from us longer than he was with us. A monument celebrates his life on the mall in Washington. He is remembered as the man with a dream at the March on Washington.

In 1968, however, Dr. King was far from the favored celebrity he is today. He was under fierce criticism for opposing the war in Vietnam. Former colleagues were scorning his commitment to nonviolence. When he went to Memphis, headlines called him “Chicken a la King.” The St. Louis Globe-Democrat termed him “one of the most menacing men in America today.” The FBI was planning COINTELPRO operations to spread rumors about him and discredit him.

The civil rights movement had succeeded in ending legal segregation. The Voting Rights Act had been passed. But Dr. King knew that his greatest challenges were still ahead as he turned his focus to poverty and equal opportunity. The war on poverty was being lost in the jungles of Vietnam as war consumed the resources needed.

Dr. King went to Memphis to support African-American sanitation workers who were striking for equal pay and for a union. His first nonviolent march there was disrupted when some of the marchers started breaking into and looting stores. King decided to return to Memphis because he believed that nonviolence was now on trial.

Dr. King was focused on organizing a Poor People’s Campaign to march on Washington, reaching out to impoverished white miners, Hispanic farmworkers, Native Americans, the urban poor. Injustice anywhere, Dr. King preached, was a threat to justice everywhere.

Dr. King decried the unemployment that was so crippling to the black community. But he also knew, even then, that a job no longer guaranteed a way out of poverty. “Most of the poverty-stricken people of America,” he said, “are persons who are working every day and they end up getting part-time wages for full-time work.”

So Dr. King went to Memphis to march with sanitation workers — and there his life was taken from him.

Now, 45 years later, his last mission is still unfulfilled. One in five children in America are at risk of going without adequate nutrition. One in three African-American children. Forty-six million Americans are in poverty. More than 20 million people are in need of full-time work. African-American unemployment remains twice the rate of whites.

Dr. King knew that these conditions would not change unless working people and the poor joined across lines of race and religion and region to demand justice. Nothing would change unless people disrupted business as usual, with nonviolent protest, expressing their own humanity while exposing the inhumanity of the current arrangements.

On April 4, many will remember Dr. King. The news programs will rebroadcast parts of his sermon the night before he was shot when he promised those gathered that they would “get to the promised land” although “I might not get there with you.”

The way to remember Dr. King is to pick up the struggle. Poverty and inequality, he taught us, are a threat to democracy and to freedom. And only nonviolent engagement by people of good conscience joining with those who are afflicted can possibly drive the change we need.

Today, inequality has reached even greater extremes. Wages are sinking, poverty is spreading. In this rich nation, poor children go hungry. The Poor People’s Campaign that was lost in the wake of war and the assassinations of Martin Luther King and Robert Kennedy is needed now more than ever.